In these years, a heat assist recording scheme is attracting attention as a technology that enables high density magnetic recording of a 1 Tbit/inch2 class. In the heat assist recording scheme, laser light generated by a light source (laser diode) is converted by a near field transducer into near-field light to be irradiated onto part of the surface of a magnetic disk so as to raise the temperature of the magnetic disk locally. Then, by applying a magnetic field to the temperature-raised part of the magnetic disk by a magnetic field generating element, data is recorded magnetically. At this time, it is desired to improve data reliability.